00319nam a2200121Ia 4500082001700000100002000017245004800037260003600085300002700121490003900148500000500187700000500192 a512bC537.CI aChilds, Lindsay aA concrete introduction to higher algebrab aNew YorkbSpringer-Verlagc1979 axiv, 338p. Index. Bibl aUndergraduate texts in Mathematics a a